java-me bluetooth file send help

Question

i am having two cell phones and i want to exchange file between these two. Device A invoke java app, it will scan available bluetooth device in range, show them into list and user can select one device and click send.

i have written below code, it is not working.

package hello;

import java.io.; import java.util.Vector; import javax.bluetooth.; import javax.microedition.io.; import javax.microedition.io.StreamConnection.; import javax.microedition.lcdui.; import javax.microedition.midlet.MIDlet; import javax.obex.; import javax.obex.ResponseCodes;

public class MyMidlet extends MIDlet implements CommandListener, DiscoveryListener {

public Command cmdSend;
public Command cmdScan;
public TextBox myText;
public List devList;
public Form myForm;
private LocalDevice localDev;
private DiscoveryAgent dAgent;
private ServiceRecord servRecord;
private Vector myVector;
    private ClientSession connection = null;
private String url = null;
private Operation op = null;
private boolean cancelInvoked = false;

public MyMidlet()
{
    cmdSend = new Command("Send", 2, 0);
    cmdScan = new Command("Scan", 5, 0);
}

public void startApp()
{
    if(myText == null)
    {
    myText = new TextBox("Dummy Text", "Hello", 10, 0);
    myText.addCommand(cmdScan);
    myText.setCommandListener(this);
     Display.getDisplay(this).setCurrent(myText);
    }
}

public void pauseApp(){}
public void destroyApp(boolean flag)  { }

public void commandAction(Command command, Displayable displayable)
{
    if(command == cmdScan)
    {
        if(myForm == null) { myForm = new Form("Scanning"); }
        else {
            for(int i = 0; i < myForm.size(); i++)  myForm.delete(i);

           }
        myForm.append("Scanning for bluetooth devices..");
        Display.getDisplay(this).setCurrent(myForm);
        if(devList == null)
        {
            devList = new List("Devices", 3);
            devList.addCommand(cmdSend);
            devList.setCommandListener(this);
        } else
        {
            for(int j = 0; j < devList.size(); j++)  devList.delete(j);

        }
        if(myVector == null) myVector = new Vector();
        else  myVector.removeAllElements();
        try
        {
            if(localDev == null)
            {
                localDev = LocalDevice.getLocalDevice();
                localDev.setDiscoverable(0x9e8b33);
                dAgent = localDev.getDiscoveryAgent();
            }

            dAgent.startInquiry(0x9e8b33, this);
        }
        catch(BluetoothStateException bluetoothstateexception)
        {
            myForm.append("Please check your bluetooth is turn-on");
        }
    }
    if(command == cmdSend)
    {
        myForm.setTitle("Sending");
        for(int k = 0; k < myForm.size(); k++)  myForm.delete(k);

        myForm.append("Sending application..");
        Display.getDisplay(this).setCurrent(myForm);
        try
        {
            RemoteDevice remotedevice = (RemoteDevice)myVector.elementAt(devList.getSelectedIndex());
            dAgent.searchServices(null, new UUID[] {new UUID(4358L)}, remotedevice, this);
            return;
        }
        catch(BluetoothStateException bluetoothstateexception1)
        {
            myForm.append("could not open bluetooth: " + bluetoothstateexception1.toString());
        }
    }
}

public void deviceDiscovered(RemoteDevice remotedevice, DeviceClass deviceclass)
{
    try
    {
       devList.append(remotedevice.getFriendlyName(false), null);
    }
    catch(IOException _ex)
    {
        devList.append(remotedevice.getBluetoothAddress(), null);
    }
    myVector.addElement(remotedevice);
}

public void servicesDiscovered(int i, ServiceRecord aservicerecord[])
{
    servRecord = aservicerecord[0];
}

public void serviceSearchCompleted(int i, int j)
{
    if(j != 1) myForm.append("service search not completed: " + j);
    try
    {
        byte[] fileContent = "Raxit Sheth -98922 38248".getBytes();
        String s=servRecord.getConnectionURL(0, false);
        myForm.append("Debug 0");
        connection = (ClientSession) Connector.open(s);
        myForm.append("Debug1");
        HeaderSet headerSet = connection.connect(null);

        myForm.append("Debug1.1");
        headerSet.setHeader(HeaderSet.NAME, "a.txt");
        headerSet.setHeader(HeaderSet.TYPE, "text/plain");
        headerSet.setHeader(HeaderSet.LENGTH, new Long(fileContent.length));
        myForm.append("Debug1.2");
        //op = connection.put(headerSet); throwing java.lang.IllegalArgument.Exception
        op = connection.put(null);
        myForm.append("Debug1.2.1");
        op.sendHeaders(headerSet);
        myForm.append("Debug1.3");
        OutputStream out = op.openOutputStream();
        myForm.append("Debug2");
        //sending data
        myForm.append("Debug3");
        out.write(fileContent);
        myForm.append("Debug4");
        //int responseCode = op.getResponseCode();
        //myForm.append("resp code="+responseCode);

        out.close();
        op.close();
        connection.close();
        myForm.append("Done");
        //i was expecting this will send  a.txt file with content Raxit Sheth -98922 38248
        //to remote device's inbox/gallery/bluetooth folder
    }
    catch(Exception ex) {  myForm.append(ex.toString());   }
}

public void inquiryCompleted(int i)
{
    Display.getDisplay(this).setCurrent(devList);
}  

}

Answer 1

Your problem is almost certainly the fact that you're starting your bluetooth scanning in the commandAction() method. This is a system lifecycle method, and needs to return quickly. Attempting to perform a blocking operations (such as bluetooth scanning) in this thread could tie up resources which the handset needs to do other things such as the actual scanning!

Refactor so that the scanning is performed in a new thread, then try again.